The formation of N-nitrosamines, many of which have been shown to be carcinogenic in experimental animals, is a relatively facile chemical reaction. The amine precursors occur widely in foods and nitrite is used as an additive in the manufacture of cured meat products. Recent research has shown that N-nitrosamines can form during the direct-fire drying of foods. Presumably amines in the food being dried are nitrosated by oxides of nitrogen in the flue gases. In a broad sense the purpose of this research is to investigate the occurrence and formation of N-nitrosamines in our food supply. The N-nitrosamine content of direct-fire dried foods will be determined. Initially these foods will be analyzed for volatile nitrosamines by GC-TEA (0.1 ppb) and volatile nitrosamines will be confirmed by GC-MS (1.0 ppb). Analytical methods for the determination of nonvolatile nitrosamines in foods will be developed and evaluated. Efforts will focus on the differentiation between nonvolatile nitrosamines and nitrosamides. Nitrosamides will be destroyed by treatment with base prior to analysis for nonvolatile nitrosamines. Procedures for the extraction of nonvolatile nitrosamines from foods and methods for estimation of the individual compounds by HPLC-TEA will be developed. The N-nitrosation reaction will be studied in foods dried using commercial direct-fire drying processes. Green malt will be used initially since it is know that N-nitrosation occurs readily when this product is subjected to direct-fire drying. Characterization of the nitrosating species and elucidation of the mechanism by which SO2 inhibits N-nitrosation in the direct-fire drying of malt are factors which will be included in the study. Experiments will be carried out to determine the potential of different foods for N-nitrosation under strong nitrosating conditions, and under simulated gastric conditions.